Option 3: Sell 135i, buy 1M. At some point it is actually cheaper. All that body work adds up. Also, the 1M will have much better resale and liquidity than a customized 135i so the actual economics could work out better long term.
2009 BMW 135i, 6 MT, M Sport, DIY DCI, Cobb AP, Apex 18x8.5+9.5, 235/265 Starspecs